Aquarium Co2 Indicator Glass Tester Kit 15ml | Fish Tank Plants Monitor | Diy. Aquarium CO2 Indicator Fish Tank Glass Liquid Tester Description Ensure the Optimal Health and Growth of Your Aquarium Plants with This Easy-to-use Aquarium CO2 Indicator. With a 15ml Test Solution Capacity, This Device Helps You Monitor the CO2 Levels Essential for Your Aquatic Environment. The Indicator, Available in Musical Note, Ball, Water Drop, and Hook Models, Provides Clear Visual Feedback by Changing Colors to Represent CO2 Concentration Levels. Blue Indicates Low CO2 and Slow Plant Growth, Green Shows Normal Levels Safe for Aquatic Life, and Yellow Warns of Excessive CO2 That May Harm Fish and Shrimp. Crafted from Corrosion-resistant Glass, This Aesthetically Pleasing Device is a Reliable Addition to Any Aquarium Setup. Remember to Replace the Test Solution Monthly for Accurate Readings. Features - Visual Color Indicator for CO2 Concentration - Glass Construction: Corrosion-resistant and Stylish - Available in Four Design Models - Easy Maintenance: Monthly Solution Replacement Package Includes - 1 Set X Indicator + Solution.